Development of soft sensor exterior embedded with multi-axis deformable tactile sensor system

In some important robotic human daily life support applications, such as housework or nursing care, soft sensor exterior is needed for allowing close contacts against humans or environments. Although there are many studies on tactile sensing elements themselves and some of them realize the mechanical softness of the element, most of their studies just propose their detection theory with their sensor element prototypes and it is difficult to use them for developing soft tactile exterior. Therefore a soft sensor exterior embedded with multi-axis deformation sensor is developed in this paper. The most important feature for this sensor is that it can detect multi-axis deformation, and the sensor element itself has enough softness to deform with the outer exterior. The developed sensor is constructed by molding a soft urethane foam with infrared LEDs and corresponding phototransistors. It detects 3D deformation of the sensor as voltage changes at each phototransistors. Furthermore, a prototype of soft sensor exterior embedded with the developed sensing elements is realized and we confirmed that the 3D deformation, such as stroking, pinching, and pushing, can be detected using the developed sensor exterior prototype.